Answer:ANSWER IS OPTION 'B'
Global climate is changing due to burning of fossil fuels and deforestation.
Answer: we can make observations directly by seeing, feeling, hearing, and smelling, but we can also extend and refine our basic senses with tools: thermometers, microscopes, telescopes, radar, radiation sensors, X-ray crystallography, mass spectroscopy, etc. And these tools do a better job of observing than we can!
The barrier is cultural differences.
John, growing up in America learned that eye contact is a way of respect and to show you are paying attention.
Where Cho, growing up in Asia, many Asian counties don't have this "custom" to call it that.